Sheet separator



Patented Nov. 25.4, 1925,

UNITED STATES PATENT OFFICE.

CARL HENDERSON, 0F CHICAGO, ILLINOIS, ASSIGNOR T0 MIEHLE PRINTING PRESS & MANUFACTURING- COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SHEET SEPARATOR.

Application led February i4, 1923.

To all whom t may concern.'

Be it known that I, CARL HENDERSON, :i citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in a Sheet Separator, of which the following is a specification.

This invention relates to a sheet separator.

@ne obgect of the invention is to provide a simple and eiiicient sheet separator' which is capable of separating the top sheet from second sheet in a commercially satisfactory manner, such as is necessary, for example, in connection with the usc of printing presses.

Another object is to provide the kind of sheet separator above referred to which is capable of functioning efficiently on paper varying greatly in thickness and stiffness.

hese and other objects are accomplished by means of the arrangements shown on the accompanying sheet of drawings, in which- Figure l is a fragmentary side elevation of a sheet separator embodying my invention, the supporting` bar therefor being shown in section;

Figure 2 is a bottom plan view of the suction shoe proper;

Figure 3 is a sectional view taken in the plane of line 3 3 of Figure 2;

Figure l is a bottom plan view of a slightly modified suction shoe; and

ligure 5 is a sectional view taken in the plane of line 5--5 of Figure 4l.

The various novel features of the invention will be apparent from the followingl description and drawings and will be par'- ticularly pointed out in the appended claims.

ln the Cheshire TPatent No. 1.194,32? dated August 8, 1916, there is disclosed and claimed in its broadest aspect a suction shoe for separating the top sheet from the remainder of the pile of stock, said shoe having a suction cup in the lower side thereof and having such lower side formed to prevent the creation of vacuum spaces between the top and second sheet at the parts of said sheets embracing said suction cup, or to create between the first and second sheets an air chamber embracing the edges of said suction cup and in communication with the atmosphere, the theory being that the formation of vacuum spaces beween the top and second sheets, due to leakage of air Serial No. 618,923.

through the top sheet into the suction opening or cup of the shoe, is avoided on account of air being admitted between the sheets.

In a Cheshire application Serial No. 464k,i 82, tiled April 25, 1921, there is disclosed a radically different and characteristically distinctive type of suction shoe. In connection with this second suction shoe, the theory is to provide at all times an exposed air space or spaces between the suction shoe and the top sheet of paper, the suction opening in the shoe being in direct communication with said exposed air space or spaces, when the shoe is placed upon the top sheet of material, so that any leakage of air will be from the air space or spaces over the sheet to the suction opening instead of a leakage of air through the top sheet. The suction is sulficiently great to draw the top sheet of Inaterial up into a groove in the under surface of the shoe but not strong enough to extend through the top sheet to draw the second sheet, especially in view of the airleakage over the top sheet. The top sheet, as it recedes from the next sheet on the pile, gradually cuts olf communication between the suction opening in the shoe and the exposed air spaces above said top sheet. When the top sheet is drawn up completely into its limiting position within the suction groove, communication between the suction opening and the exposed air spaces is cut off entirely. Art this time, however, the top sheet is in a remote position with respect to the second sheet, whereby said top sheet is effectively separated from the second sheet land may be fed to suitable impression means.

The theories of operation of these two characteristically different and distinct types of suction shoes have been described to indicate generally the prior art before describing the theory of operation of my present invention covering still another distinct type of suction shoe.

The theory on which my suction shoe operates to separate the top sheet from the second sheet is that the top sheet should be acted upon by suction extending through openings in surfaces at different levels on the bottom of the shoe, said surfaces being separated by shoulders lying in diverging planes and over which the top sheet tem- CII porarily is relatively sharply crimped or buckled, the action of the various parts of the shoe preventing the adherence of the second sheet when the top sheet is acted upon. More specifically, as to some structural details, there are a` plurality of slightly elevated suction openings at the extreme forward end of the shoe which openings are brought into association with the extreme front or advanced edge of the top sheet so that a relatively large portion of the advanced edge of the top sheet is separated from the second sheet, there preferably being another suction opening to the rear and at a lower level on the shoe so that these cooperating suction openings upon different levels or in different planes, upon becoming effective substantially simultaneously, temporarily put a sharp crimp or buckle into the top sheet for quickly establishing' a relatively large air space between the top and second sheets to insure good separat-ion. In applying this theory it has been established that best results are obtained by having the two lower suction surfaces, as it were, separated by shoulders lying in lines diverging from a point near the front edge of the shoe, the rear suction opening` being substantially at the apex of and within a formed angle.v

The pointed end of the lower suction surface acts to prevent buckling of the second sheet and also frictionally sticks into the top sheet as the latter is pulled from the p ile. This suction shoe', unlike others, prevents the formation of a suction cup between the shoe and top sheet, and of course no suction pocket is formed between the top and second sheets. In addition the sheet being separated is not stretched. 1n the theory of operation of my suction shoe it is to be made clear that the suction which is used to pick up the top sheet is not strong enough to extend through the top sheet and, accordingly, the second sheet, in so far as suction is concerned, is not lifted with the top sheet.

Referring to the figures of the drawings, it will be noted that the suction shoe 10 is rockably supported within suitable bracket means 11, which in turn is secured in any suitable manner to a supporting bar 12. The suction shoe at its sides near theI front end, is provided with lateral extensions 13 which are received by suitable elongated slots 14 in the bracket means 11. Also proliecting from the sides of said suction shoe near the rear thereof are lateral extensions 15, which are operatively received by relatively large slots 16, which permit the rear end of the shoe to rise` and fall about the front lateral projections 13 as a pivot; The rear end of the shoe 10 is heavier than the front end and accordingly, as the shoe is lowered the rear end thereof is at a lower level, the front end assuming the same level on the top sheet when the shoe has been completely lowered and rests upon the top sheet. As the shoe is raised, the front end thereof leaves the pile first, the rear end of the shoe following as indicated in Figure 1 of the drawings. The shoe is provided with a relatively large suction cavity 17, and a short tube 18 extends through the top of the shoe 10 and communicates with said cavity, it being understood that the tube 18 is connected to any suitable source of vacuum through a flexible tube 19.

Referring particularly to Figures 2 and il, it will be noted that the bottom of the suction shoe is provided with two relatively large separate surface portions 19 and 20 which lie in two different planes substantiaily parallel to each other. rfhese plane surface portions which are separate from each other, lare defined by shoulders 21 which lie in lines diverging rearwardly from a point near the front of the shoe, and as will be pointed out more fully later, the top sheet in being separated from the second sheet is caused to temporarily crimp or buckle along these diverging shoulders 21. `Within the triangle, two sides of which are formed by the shoulders 21, and near the apex, a suction opening 22 in the lower surface 20, which opening entends from the suction cavity 17. A plurality of suction openings 23 extend from the suction cavity 1.7 through the upper surface 19 at the bottoni of the shoe and in a straight line directly adjacent the front edge of the shoe.

From this arrangement, it will be understood that when a suction force is exerted through the tube 18, and the shoe 10 is per initted to pass int-o engagement with the top sheet, the. suction extending through the opening 22, for a small fraction of a second, e'irst becomes effective in gripping the top sheet. immediately thereafter and almost instantaneously, suction extending through the other suction openings 23 at the front edge of the shoe grip the top sheet and, as a result of this cooperative action, the top sheet temporarily is crimped or buckled over the shoulders 21 causing an immediate separation of a large front or advance portion of the top sheet. it is due to this peculiar buckling action that a large area between the top and second sheets is exposed to the air for facilitating separation of the top sheet. The suction extending through the opening 22 makes the buckle sharper than it otherwise would be. Furthermore the point 24 at which the shoulders meet, acts in a manner to prevent buckling of the second sheet, and it also sticks into the top sheet frictioruilly to prevent slipping thereof as the latter is pulled from the pile. It is apparent that no suction cup or space is formed between the suction shoe and the top sheet, and in view of the fact that the suction does not extend through the top sheet, no

suction cup or space is formed between the (op and second sheets. Furthermore by having no suction cup formed between the shoe und top sheet, the latter .is not pulled or stretched as in certain other forms of shoes. By providing the shoe with a relatively large flat bottom surface 20, the sheet being operated upon is better controlled in a separating action Vthan otherwise would be the case.

The suction shoe shown in Figures and 8 is effective for separating sheet material. varying greatly in thickness and stiffness and it is especially effective in saparating lighter grades of sheet material.

ln Figures el and 5, a slightly modified foi-m of suction shoe is disclosed which is particularly adapted to separate heavier sheet material. lt differs from the suction slice shown in Figures 2 and 8, primarily in having larger suction openings 25 near the front edge of the slice and having a large suction opening 26 in the lower triangular portion. lt will be noted also that opening 5@ is not located so close to the apex of the triangle as the opening 22 shown in Figures and 3 and that shoulders 27 formed between the upper and lower surfaces 28 and Q9 at the bottom of the shoe diverge from each other more abruptly and meet at their forward ends in a curved line 30. While the upper and lower surfaces 28 and 29 of the suction shoe shown in Figures l and 5 are in different planes, said planes intersect each other instead of being substantially parallel as is the case with the shoe shown in Figures 2 and 3. The operation of the suction shoe shown in Figures l and 5 is substantially identical with that of the shoe shown in Figures 2 and 8, but as mentioned above, it is particularly adapted for separating relatively heavy sheet material.

lt is my intention to cover all modifications of the invention falling within the spirit and scope of the following claims.

l claim:

ll. l suction shoe for separating one sheet of material from another, comprising a body the bottom of which lies in two planes which are separated by shoulders lyin, along diver-Ging lines, there being a Sil(V non opening` in each of said two planes bottom, whereby the sheet is buchover said shoulders in diverging lines f" ely separating the top sheet and ing the withi'lrawal thereof from second sheet.

a. fr suction shoe for separating one sheet ol material from another, comprising a tlie bottom of which lies in two a one' dii'crging lines, there being a ening in each of said two suriid bottom, whereby the sheet is over said shoulders in diverging :es which are separated by shoulders of material from another, comprising aV1 body, the bottom of which lies there being a plu ity of suction openings near the front et of said shoe in one of said planes and another' suction opening rearwardly therefrom in the second plane, whereby the top sheet is caused to buclrle between said two planes for etlle'fively separating said top sheet and fa Ltating the removal thereof from the seconil sheet.

Lt. A suction shoe for separating one sheet of material from another, comprising a body, the bottom of .which lies in two planes which are separated by shoulders lying along diyerging lines, there being a suction opening near the front edge of said slice in one of said planes in advance of said shoulder and a suction opening in the other plane to the rear of i shoulders. whereby the top sheet is 'bu ed over said shoulders in diverging lines lor effectively separating the top sheet and facilitating thc withdrawal thereof from the seconu sheet.

5. 1;. suction slice for separating one sheet of material from another, comprising a body, the bottom of which lies in two planes which are separated by shoulders lying along diiferging lines and ini-)sting in a point, there being a suction opening in advance of and to the rear of said point in said different planes whereby the top sheet is buckled over said shoulders, and said point intimately frictionally engaging said top sheet for effectively separating said top sheet and facilitating the withdrawal thereof from the second sheet.

6. A suction shoe for separating one sheet of material from another, comprising a body, the bottom of which lies in two planes in two planes,

separated by diverging shoulders, the lower plano surface being relatively large as conipared with the upper plane sur ace, there being a suction opening in the upper plane surface adjacent the front edge of said shoe and a suction opening in the lower plane surface within said shoulders whereby the top sheet is buckled over said shoulders in diverging lines for efectively separating the top sheet and facilitating .the withdrawal thereof from the second sheet.

7. A suction shoe for separating one sheet of material from another, comprising -a body, the bottom of which lies in two planes which are separated by shoulders lying along diverging lines, there being an opening in the upper plane in advance of said shoulders, whereby the sheet is buckled over said shouluers in diverging lines for effectively separating the top sheet and facilitating the withdrawal thereof from the second sheet.

S. A suction shoe for separating one sheet of material 'from another, Comprising a body, the bottom of which lies in Anwo plaines whivh are separated by shoulders lying` 5 along` (livel-ging lines, there being an opening in one o'l said planes in proximity lo seid shoullle', whereby the sheet is buclill over said shoulders in diverging lines for effectively separating the top sheet and fn- Clitating the withdrawal thereof from the second Sheet.

Signed at Chi fargo, Illinois, this; 9th day of February, 19223,

CARL HENDERSON. 

